The present invention relates to the data recording method, the data output method, and the data recording and/or reproduction method. More specifically, the present invention concerns the data recording method, the data output method, and the data recording and/or reproduction method of recording, reproducing, outputting, and duplicating content data in which copy management information or reproduction management information is embedded as a watermark.
In recent years, there is an increasing demand for copy protection and copyright protection of digital works and digital contents with the spread of recording media such as DVD (Digital Versatile Disc), the Internet, digital satellite broadcasting, etc. Digital contents such as video and voice are converted to analog signals so as to be audiovisually presented. There is examined a technology which can maintain relatively excellent sound or image quality and prevent an unauthorized copy in analog or compressed copies.
For example, SDMI (Secure Digital Music Initiative) etc. are promoting the actual use of an electronic watermark which persists after an analog or compressed copy of the content.
In this case, the proposed watermark is embedded in an analog or digital signal so that the watermark does not have an unfavorable effect on video and voice signals and is not easily tampered.
The watermark can comprise copy management information and/or reproduction management information. For example, the watermark contains information for the copy generation management such as allowing a copy for only one generation, inhibiting a copy for the second generation or later, etc. It is intended to restrict not only recording (copying), but also reproduction at the time of reproduction for full protection against an unauthorized copy or a so-called pirated copy.
For example, there are specified one-generation copy permission and copy inhibition for copy generation management. In the case of recording (copying) content data embedded with a watermark indicating one-generation copy permission, it is proposed to apply processing such as rewriting the watermark to that indicative of the copy inhibition.
A watermark embedded in analog or digital signals must be protected against modification etc. by suppressing effects on content signals, especially by preventing degradation of these signals. Generally, detecting or attaching this watermark complicates signal processing and causes a heavy load.
When a content provider produces a master disc etc., it is possible to carefully embed a watermark by using high-performance hardware or taking sufficient time as needed so as to maintain the quality of music, video, etc. When a user copies data by using a commercially available recording apparatus, it is impossible to expect the throughput equivalent to that of the provider. Since a realtime or higher copy operation is required, it is difficult to embed the watermark at the same level as the provider.
The present invention has been made in consideration of the foregoing. It is therefore an object of the present invention to provide a data recording method, a data output method, a data recording and/or reproduction method, a data duplication control method, and a recording medium processing apparatus for decreasing loads of rewriting a watermark embedded in contents.
In order to solve the above-mentioned problems, the present invention provides a method of recording data embedded with management information including at least copy management information, wherein part of the management information embedded in the data is modified, is embedded in the data as new management information, and then is recorded.
Further, in order to solve the above-mentioned problems, the present invention provides a method of outputting data embedded with management information including at least one of copy management information and reproduction management information, wherein the method modifies part of the management information embedded in the data, embeds the modified management information as new management information in the data, and then outputs data.
Moreover, the present invention provides a method of outputting data embedded with data management information including at least one of copy management information and reproduction management information, wherein the method modifies part of the management information embedded in the data to create new management information and reads the new management information embedded in the data from the data, the method further comprising: statistically processing the read new management information and identifying the read new management information; and controlling recording or reproduction of data controlling recording or reproduction of the data based on the identification result.
Furthermore, the present invention provides a method of duplicating data embedded with data management information including at least copy management information, wherein the method modifies part of the management information embedded in the data to create new management information and reads the new management information embedded in the data from the data, the method further comprising: statistically processing the read new management information and identifying the read new management information; and controlling output for the data duplication based on the identification result.
Still further, the present invention comprises a head section which uses a recording medium recording data embedded with management information including at least one of copy management information and reproduction management information and reads the data from the recording medium; an extraction section which extracts the management information from the data read from the recording medium by the head section; an identification section which identifies the read management information extracted by the extraction section; a control section which controls duplication or reproduction of the data based on an identification result by the identification section; and a processing section which is controlled by the control section and, when the data is output for duplication, modifies part of the management information embedded in the data to embed the modified management information as new management information in the data.